PHOENIX -- After taking a Barry Zito curveball to the helmet on Saturday, right fielder Nyjer Morgan was happy to be the butt of an old joke when the tests of his head came back Sunday morning and revealed there was nothing there.

Morgan sat out Sunday's tilt, however, as the Brewers took extra precautions.

"He's fine," manager Ron Roenicke said. "He's able to play, but we thought with the off-day tomorrow, we'd just give him off today. He's going to hit extra and do some extra work here. We really don't need to do this, but it kind of makes sense."

Morgan was hit in the top of the first inning and stayed on base and took the field in the bottom of the frame before coming out as a precautionary move in the second inning. He's in the mix as a potential starter in right field, depending on Corey Hart's recovery from arthroscopic knee surgery. Hart has progressed well and has an outside chance to be with the club for the April 6 opener.

"They say three to four weeks [to recover from knee surgery], and where that puts him is right, at the earliest, on that Opening Day," Roenicke said. "He's come along really well. He's walking around here without his crutches. His range of motion is farther along than what they thought it was going to be. Those things are hard to tell."

In other medical news, Shaun Marcum played catch again Sunday after throwing successfully Saturday, and Brandon Kintzler underwent an X-ray of his right arm.

"We're trying to figure out why he can't let it go like he wants to," Roenicke said of Kintzler. "We saw it earlier in camp. The BP he threw the other day was OK, but he's still not really letting it go."

Lucroy solidifying place behind plate

PHOENIX -- Brewers manager Ron Roenicke couldn't ask for much more from his catcher than the solid spring performance Jonathan Lucroy has put on as he prepares for his second full season as the starting backstop. Lucroy entered Sunday hitting .636 (7-for-11) with three doubles, a homer, and two RBIs.

"Luc is going to keep getting better and better," Roenicke said. "He'll certainly be better this year than he was last year. I think he'll continue to grow that way. I think he'll be better offensively, too. He's a good hitter. We saw flashes last year, where he had a great month and then he'd tail off. I think he'll be more consistent."

What Roenicke is really looking forward to is the quantum leap that can take place as a catcher gets even more familiar with his pitching staff.

"The longer that you're used to a catcher, the more you start thinking on the same page," Roenicke said. "It makes a difference when a pitcher's thinking of a certain pitch, and, boom, the catcher gives it to him. It helps him with his confidence. If he's always looking in there and he's thinking a pitch and he's getting something different, sometimes there's a question of, 'Which one should I be throwing?' You don't want doubt in a pitcher's mind."

Lucroy is benefiting from extra time with bench coach Jerry Narron, a former big league catcher. A spring injury in 2011 kept Lucroy from some of the fundamental work that is making a big difference so far in the 2012 Cactus League season.

"He blocks well, but it's a matter of keeping that ball in close when he blocks," Roenicke said. "He throws well, but he's got to be more accurate with the throws. He'll get more consistent in all that. He's young, and the confidence [will come]. Once he's totally confident in his whole game, he's going to be a better player."

Perez hospitalized with collapsed lung

PHOENIX -- Brewers reliever Juan Perez was admitted to Maryvale Hospital on Sunday morning with a partially collapsed left lung. Perez is expected to remain in the hospital while recovering and could miss up to a week of baseball.

"It's a real tough break for him," manager Ron Roenicke said. "Let's hope he's not out too long. It's certainly enough to keep him in the hospital for a little bit."

Perez, 33, has played in parts of three seasons for the Pirates and Phillies, posting a 1-1 record with a 4.79 ERA in 32 relief appearances. The left-hander was a non-roster invitee to Spring Training and pitched well enough early on to gain serious consideration for the bullpen, yielding no runs and two hits while striking out two over the course of three appearances and 3 1/3 innings.

"He was throwing the ball great," Roenicke said. "He opened up a lot of eyes here. You always feel for the guy when he's doing that well and he's got a chance and then something happens."

Gallardo overcomes inconsistent command

PHOENIX -- Brewers ace Yovani Gallardo continued his strong spring with a second scoreless start on Sunday. He had occasional lapses in command, but was able to deliver when needed and kept the Rockies in check.

"Yo was real good again," manager Ron Roenicke said after his club's 5-4 victory. "He threw some balls up in the zone, but there was good life on his fastball. He threw quite a few good changeups, nice to see. He had one real good curveball that was hit pretty hard -- I was surprised."

Gallardo's biggest challenge came in the second inning when his offspeed pitches were consistently high. He gave up singles to Michael Cuddyer and Chris Nelson, then with two outs, he walked Ben Paulson to load the bases.

"I had trouble commanding the ball that whole inning," Gallardo said. "My curveball that [Nelson] hit down the line was up. The pitches were just up. I was rushing to home plate a little bit too quick, but I was able to correct that the following inning."

Gallardo threw an otherwise efficient 45 pitches over 3 1/3 innings, allowing three hits and a walk while striking out two.

"That's where it all starts, just getting ahead and then commanding the ball," Gallardo said. "I'm really focused on throwing strikes with my offspeed stuff, the slider and the curveball, and I've been working on the changeup and mixing it in for strikes around the zone."